Improved draw-bridge



@initrd itzsutfi @tutti @Mitre NEIL MAONEALE, OliVOl-NCINNAII, OHIO.

` Letters Patent No. 100,910, elated March 15, 1870.

IMPROVE!) DRAW-BRIDGE.

, The Schedule referred to in these Letters Patent and making part of the same.

To whom. 'it may concern Beit known that I, NE1L MACXEALE, of Cincinnati, Hamilton county, Ollio, have\invented a new and useful 1m provenient in Draw-Bridges; and I hereby declare the ibllowiug to be a full, clear, and exact description thereof, reference being had to the accompanying drawings making part ofths specificat-ion.

My improvement consists essentially of a tubular or Vother bridge sectiouor sections, which, when greater headway is desired, is capable ot' being elevated bodily by hydraulic cylinders, or other mechanical devices.

Figure 1 is a partly sectionized longitudinal elevation ot'a bridge-span with my supporting and elevating devices.

Figure 2 is a vertical section at the line x-a.

A A' represent twopiers.

B is a bridge-span or section, and may be, a metallic or wooden truss-trunk or tube of any one of the rigid forms now customarily employed.

The section B, when in its normaler lowest position, rests on suitable shoulders, a, in the piers, and when elevated from said shoulders is contined in vertical guides C, in said piers.

D D are hydraulic cylinders or jacks, of which there is-oue .or more under each end of the span.

These jacks, being operated by a steam-engine or other suitable power, are employed to elevate the section bodily whenever a greater headway is desired below the bridge. v

Counterbalances E, attached to the movable span B by chains or wire cables G, passing over pulleys l", may be employed to relieve the elevating mechanism oi' unnecessary labor.

While preferring the hydraulic jack for the elevating instrumentality, it is proper to state that the object may be accomplished by means oi' screws, or the direct action of steam itself.

Two or more elevatable sections maybe used in `one bridge.

My drawer has, over the customary form of swinging draw-bridge, several advantages, among the most prominent of which is the avoidance of a pivot-pier, which, in the common form, diminishes the available passage more than one-halt', and is costly of construction.

Another advantage of my form` exists in the fact. oi its greater security against winds, e., because of its ends being always securely heldby the piers when elevated, as much as in its resting position.

I claim herein as new and of my invention- 1. A draw-bridge, consistingof a rigid and elevatable section, guided and operated substantially as set forth.

2. A bridge, having one or more sections capable of temporary elevation, as and for the purpose set forth.

1n testimony of which invention I have hereunto set luy-hand.

NEIL MACNEALE.

Witnesses GEO. H. KNIGHT, JAMns H. LAYMAX. 

